Preheat the oven to 350°F and grease a loaf pan with nonstick cooking spray and line the long edge with parchment paper, leaving some overhang on the sides.
Whisk the together the pumpkin puree, melted butter, brown sugar, eggs, and vanilla in a large bowl.
1 1/2 cups pumpkin puree, 1/2 cup unsalted butter, 1 cup light brown sugar, 2 large eggs, 1 teaspoon pure vanilla extract
Add the flour, baking powder, baking soda, pumpkin pie spice and salt, and mix until just combined.
1 3/4 cup all-purpose flour, 1/2 tsp baking powder, 1 tsp baking soda, 1 1/2 teaspoons pumpkin pie spice, 1/2 teaspoon kosher salt
In a separate small bowl, mix together the cinnamon and granulated sugar to make the cinnamon swirl.
3 teaspoons cinnamon, 1/2 cup granulated sugar
Spoon half the pumpkin bread batter into the prepared loaf pan. Sprinkle generously with the cinnamon sugar, reserving 2 tablespoons for topping the loaf. Add the remaining batter over the sugar. Run a knife down the center of the loaf 1-2 times to gently swirl the sugar. Sprinkle the remaining cinnamon sugar over top of the batter.
Bake in the preheated oven for 60-70 minutes or until a toothpick inserted in the center comes out clean. Begin checking it at 50 minutes and tent the bread with foil if the top is starting to look too brown.
Remove from the oven and allow it to cool in the pan for 15 minutes then use the parchment overhang to remove it from the pan and finish cooling on a wire rack.